Large roasting furnace

Abstract

The large roasting furnace comprises a furnace body, a furnace cover and a central cylinder, the furnace cover is arranged at the upper end of the furnace body in a sealed mode, a smoke exhaust pipe is arranged on the furnace cover, a furnace door is arranged on the side wall of the furnace body, the central cylinder is fixedly arranged in the middle of the furnace body, and tangential burners are arranged on the side wall of the furnace body. The central cylinder is arranged in the furnace body, the diameter of the furnace body can reach more than 15 meters, the processing scale of a single furnace can reach more than 20 m < 3 > / h, compared with an original furnace type, the load of the single furnace is improved by 70%, the production efficiency can be effectively improved, and the production cost can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of roasting furnaces, and particularly to a large roasting furnace. Background Art

[0002] In the acid regeneration technology, an acid pickling line is required for production. The specific production process is as follows:

[0003] The first step is that the waste acid liquid of the acid pickling line is collected in a waste acid storage tank. The storage capacity of the waste acid storage tank ensures the independent continuous operation of the acid regeneration station from the acid pickling line;

[0004] The second step is to pump the waste acid in the storage tank to an acid filter to separate and filter the solid particles and undissolved residues generated during the acid pickling process;

[0005] The third step is that the filtered waste acid enters the bottom of the pre-concentrator through a pneumatic valve. The pneumatic valve automatically controls the liquid level at the bottom of the pre-concentrator. The constant amount of waste acid flows from the pre-concentrator into a circulation pump for circulating spraying, and directly exchanges heat with the hot gas of the roasting furnace for evaporation and concentration;

[0006] The fourth step is that the concentrated waste acid is pressed into the top lance of the furnace by a roasting furnace pressure pump to control the flow rate. The lance is equipped with a nozzle and can be automatically immersed in the furnace chamber. A filter is equipped on the lance to prevent the nozzle from being blocked. In the hot zone in the furnace chamber, FeCl 2 undergoes thermal decomposition according to the following formula: 2FeCl 2 +2H 2 O+1 / 2O 2 =Fe 2 O 3 (s)+4HCl(g);

[0007] The fifth step is that the primary iron oxide powder generated at the top of the furnace is in the shape of a hollow sphere with a diameter of about 0.2 μm. During the falling process, it floats due to the entrainment of the countercurrent eddy gas, and when it encounters the spraying acid liquid again, the particle size gradually grows. The iron oxide falling to the bottom of the furnace is also in the shape of a hollow sphere with a diameter of about dozens of microns and is discharged through a sealed rotary valve. A thermal screw conveyor with a small burner is installed below the rotary valve to further reduce the residual chlorine content in the oxide by combustion. The gas returns to the roasting furnace, and the Fe 2 O 3 powder enters the bagging machine through the bottom sealed rotary valve of the bin.

[0008] With the development of China's iron and steel metallurgy industry, especially the rapid development of hydrometallurgy in the non-ferrous metal industry in recent years, the demand for large-scale roasting furnaces is becoming increasingly urgent. However, due to the limitation of the furnace type of the current roasting furnace using the spray roasting method, the temperature gradient is too large. Especially in the area located at the center of the furnace, since the temperature near the furnace wall cannot be too high, the temperature at the center of the furnace will be lower as the furnace diameter increases, which will inevitably seriously affect the acid recovery rate. The limit of the waste acid treatment capacity of a single furnace is 12 m 3 / h. If the processing load continues to increase, the required diameter of the roasting furnace will be too large, making it difficult to meet the process requirements. Summary of the Invention

[0009] The object of the present invention is to overcome the deficiencies of the prior art and provide a large-scale roasting furnace.

[0010] The object of the present invention is achieved through the following technical solutions:

[0011] A large-scale roasting furnace includes a furnace body, a furnace cover, and a central cylinder. The furnace cover is hermetically arranged at the upper end of the furnace body. A flue gas discharge pipe is arranged on the furnace cover. A furnace door is arranged on the side wall of the furnace body. The central cylinder is fixedly arranged in the middle of the furnace body. Tangential burners are arranged on the side wall of the furnace body.

[0012] Further, the cross-sections of the furnace body and the central cylinder are both circular and coaxially arranged.

[0013] Further, the lower end of the central cylinder is connected to the inner wall of the furnace body through a lower support, and the upper end of the central cylinder is connected to the furnace cover through an upper support.

[0014] Further, a plurality of spray guns are arranged on the furnace cover, and the spray guns are arranged between the inner wall of the furnace body and the outer wall of the central cylinder.

[0015] Further, at least two of the tangential burners are evenly arranged on the side wall of the furnace body.

[0016] Further, the furnace body includes an outer shell layer, a lightweight layer, and a refractory brick layer. The lightweight layer is arranged inside the outer shell layer, and the refractory brick layer is arranged inside the lightweight layer.

[0017] Further, the flue gas discharge pipe is fixedly arranged in the middle of the furnace cover and is horizontally arranged.

[0018] Further, the furnace body includes a cylindrical section and a conical section. The upper end of the cylindrical section is hermetically and fixedly connected to the furnace cover, the lower end of the cylindrical section is hermetically and fixedly connected to the large-diameter end of the conical section, and a discharge port is arranged at the small-diameter end of the conical section.

[0019] Further, the central cylinder is a hollow cylinder.

[0020] Further, a thermometer interface is arranged on the side wall of the furnace body.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1) In the present technology, a central cylinder is arranged inside the furnace body. The diameter of the furnace body can reach more than 15 meters, and the processing scale of a single furnace can reach 20m 3Above / h, compared with the original furnace type, the load of a single furnace is increased by 70%, which can effectively improve production efficiency and also effectively reduce production costs.

[0023] 2) In this technology, multiple spray guns are arranged on the furnace cover, and a large amount of waste acid can be sprayed simultaneously for processing operations.

[0024] 3) In this technology, multiple tangential burners are evenly arranged on the furnace body, so that better temperature control can be achieved. Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the internal connection structure of a large roasting furnace;

[0026] Figure 2 It is a schematic diagram of the connection structure between the tangential burner and the furnace body;

[0027] In the figure, 1 - furnace body, 2 - furnace cover, 3 - central cylinder, 4 - flue gas discharge pipe, 5 - tangential burner, 6 - furnace door, 7 - lower support, 8 - upper support, 9 - spray gun, 10 - discharge port, 11 - thermometer interface. Detailed Embodiments

[0028] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0029] Refer to Figure 1 - Figure 2 , the present invention provides a technical solution:

[0030] A large-scale roasting furnace, comprising a furnace body 1, a furnace cover 2 and a central cylinder 3. The upper end of the furnace body 1 is hermetically provided with the furnace cover 2. A flue gas discharge pipe 4 is provided on the furnace cover 2. A furnace door 6 is provided on the side wall of the furnace body 1. A central cylinder 3 is fixedly provided in the middle of the furnace body 1. A tangential burner 5 is provided on the side wall of the furnace body 1. The lower end of the central cylinder 3 is connected to the inner wall of the furnace body 1 through a lower support 7, and the upper end of the central cylinder 3 is connected to the furnace cover 2 through an upper support 8. The central cylinder 3 is a hollow cylinder. Among them, the central cylinder 3, the lower support 7 and the upper support 8 are all made of heat-resistant steel, and are protected by refractory materials in the prior art on the outside. The furnace body 1 and the furnace cover 2 are in sealed fit connection. The upper support 8 provided on the furnace cover 2 is used to lift the upper end of the central cylinder 3, and the lower support 7 is provided on the furnace body 1 to support the upper end of the central cylinder 3. The central cylinder 3 is provided as hollow in order to reduce the mass. The upper end of the central cylinder 3 is sealed to prevent waste acid from entering the central cylinder 3, and a through hole is provided at the lower end. The tangential burner 5 is used to heat the furnace body 1. A central cylinder 3 is arranged in the middle of this roasting furnace, so that the diameter of the furnace body 1 can reach more than 15 meters, and the processing scale of a single furnace can reach more than 20m 3 / h or more. Compared with the original furnace type, the load of a single furnace is increased by 70%, which can effectively reduce the investment cost of the enterprise, improve the processing efficiency, and is also convenient for temperature control.

[0031] In some embodiments, the cross-sections of the furnace body 1 and the central cylinder 3 are both circular and coaxially arranged. Among them, the fact that the furnace body 1 and the central cylinder 3 are both circular and coaxially arranged is convenient for temperature control and also convenient for the uniform arrangement of the positions of the spray gun 9 and the tangential burner 5.

[0032] In some embodiments, a plurality of spray guns 9 are provided on the furnace cover 2, and the spray guns 9 are arranged between the inner wall of the furnace body 1 and the outer wall of the central cylinder 3. Among them, the plurality of spray guns 9 are circularly distributed and coaxially arranged with the furnace body 1. The spray gun 9 is made of Al 2 O 3 material. At least two spray guns 9 are provided, and usually five, six, etc. are provided. The spray guns 9 are arranged in the annular gap between the furnace body 1 and the central cylinder 3, effectively avoiding the problem of unsatisfactory temperature processing with too low central temperature in the original furnace type, and also completely improving the problem of the temperature gradient distribution in the furnace.

[0033] In some embodiments, at least two tangential burners 5 are uniformly provided on the side wall of the furnace body 1. Among them, the tangential burner 5 is arranged at the connection between the cylindrical section and the conical section. Two, three, four or even more tangential burners 5 can be provided. The tangential burner 5 is arranged along the tangent of the furnace body 1, and the swirling direction of the flame gas on the tangential burner 5 maintains a spiral upward shape in the annular gap. Because the annular gap area is slightly smaller than that of the original furnace type, the heat transfer effect is improved, which is beneficial to the chemical reaction in the furnace body 1.

[0034] In some embodiments, the furnace body 1 includes an outer shell layer, a lightweight layer, and a refractory brick layer. The lightweight layer is disposed within the outer shell layer, and the refractory brick layer is disposed within the lightweight layer. Among them, the outer shell layer is a stainless steel layer, the lightweight layer is an alumina material layer, and the refractory brick layer is formed by sealing and laying refractory bricks in the prior art. The alumina material layer is sandwiched between the stainless steel layer and the refractory bricks. The refractory brick layer disposed inside can not only bear high temperatures but also prevent corrosion.

[0035] In some embodiments, the flue gas discharge pipe 4 is fixedly disposed in the middle of the furnace cover 2 and is horizontally arranged. Among them, the flue gas discharge pipe 4 is arranged in an L shape. The vertical section of the flue gas discharge pipe 4 is fixedly sealed on the furnace cover 2 and is coaxially arranged with the furnace cover 2. The furnace cover 2 is arranged in a spherical shape. The flue gas discharge pipe 4 is connected to the top of the furnace cover 2, which facilitates smoke discharge. The end of the flue gas discharge pipe 4 is horizontally arranged, which prevents rainwater or foreign objects from entering the furnace body 1 through the flue gas discharge pipe 4.

[0036] In some embodiments, the furnace body 1 includes a cylindrical section and a conical section. The upper end of the cylindrical section is fixedly sealed and connected to the furnace cover 2, and the lower end of the cylindrical section is fixedly sealed and connected to the large-diameter end of the conical section. A discharge port 10 is provided at the small-diameter end of the conical section. Among them, the outer shell layer, the lightweight layer, and the refractory brick layer are all provided on the cylindrical section and the conical section. The sealing rotary valve in the background art is provided on the discharge port 10.

[0037] In some embodiments, a thermometer interface 11 is provided on the side wall of the furnace body 1. Among them, during the processing, the temperature at the top of the furnace body 1 is controlled at about 400 °C, and the temperature near the tangential burner 5 is controlled at 600 - 700 °C. Therefore, a plurality of thermometer interfaces 11 are provided on both the upper and lower sides of the furnace body 1. The thermometer interfaces 11 are used to install thermometers in the prior art.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "bottom", "one end", "top", "middle", "the other end", "coaxial", "one side", "inner", "front", "center", "both ends", etc. are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0039] In the present invention, unless otherwise clearly defined and limited, terms such as "arranged", "installed", "connected", "fixed", "hinged", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A large roasting furnace, characterized in that: The invention comprises a furnace body (1), a furnace cover (2) and a central cylinder (3); the furnace cover (2) is sealed on the upper end of the furnace body (1); a smoke exhaust pipe (4) is arranged on the furnace cover (2); a furnace door (6) is arranged on the side wall of the furnace body (1); the central cylinder (3) is fixedly arranged on the middle part of the furnace body (1); and a tangential burner (5) is arranged on the side wall of the furnace body (1).

2. A large-scale roasting furnace according to claim 1, characterized in that: The furnace body (1) and the central cylinder (3) are both circular in cross-section and are coaxially arranged.

3. A large-scale roasting furnace according to claim 1 or 2, characterized in that: The lower end of the central cylinder (3) is connected to the inner wall of the furnace body (1) via a lower support (7), and the upper end of the central cylinder (3) is connected to the furnace cover (2) via an upper support (8).

4. A large-scale roasting furnace according to claim 1 or 2, characterized in that: A plurality of spray guns (9) are arranged on the furnace cover (2), and the spray guns (9) are arranged between the inner wall of the furnace body (1) and the outer wall of the central cylinder (3).

5. A large-scale roasting furnace according to claim 1 or 2, characterized in that: At least two tangential burners (5) are evenly arranged on the side wall of the furnace body (1).

6. A large-scale roasting furnace according to claim 1 or 2, characterized in that: The furnace body (1) comprises an outer shell layer, a lightweight layer and a refractory brick layer, wherein the lightweight layer is arranged inside the outer shell layer, and the refractory brick layer is arranged inside the lightweight layer.

7. A large-scale roasting furnace according to claim 1 or 2, characterized in that: The smoke exhaust pipe (4) is fixedly arranged on the middle part of the furnace cover (2) and is arranged transversely.

8. A large-scale roasting furnace according to claim 1 or 2, characterized in that: The furnace body (1) comprises a cylindrical section and a conical section, the upper end of the cylindrical section is sealed and fixedly connected to the furnace cover (2), the lower end of the cylindrical section is sealed and fixedly connected to the large diameter end of the conical section, and a discharge port (10) is provided on the small diameter end of the conical section.

9. A large-scale roasting furnace according to claim 1 or 2, characterized in that: The central cylinder (3) is a hollow cylinder.

10. A large-scale roasting furnace according to claim 1 or 2, characterized in that: A thermometer interface (11) is provided on the side wall of the furnace body (1).

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